Drill pipe handling apparatus having improved pipe gripping mechanism

Abstract

In a drill pipe handling apparatus, a pipe gripping mechanism comprises three pipe-gripping jaws arranged to grip a pipe at locations adjacent the apices of a triangle containing the axis of the pipe. A first pipe gripping jaw is connectible to a first pivoted arm at any selected one of a set of plural distances from the pivot axis of the first arm and connected to the first arm at one of those plural distances, and a second jaw is connectible to the second arm at any selected one of the same set of plural distances from the pivot axis of the second arm and connected to the second arm at the same one of those plural distances at which the first jaw is connected to the first arm. Because the same first and second jaws are connectible to the arms at plural distances from the pivot axes, the same jaws can accommodate a wide range of pipe diameters.

The invention claimed is: 
     
       1. A drill pipe handling apparatus comprising:
 a pipe gripping mechanism, said pipe gripping mechanism comprising: 
 a support frame; 
 first and second arms connected to said support frame and movable relative to said support frame respectively about first and second pivot axes; 
 a first actuator connected to said first arm and said support frame for moving said first arm about said first pivot axis; 
 a second actuator connected to said second arm and said support frame for moving said second arm about said second pivot axis; 
 a first jaw connectible to said first arm at any selected one of plural distances from said first pivot axis and connected to said first arm at one of said plural distances; 
 a second jaw connectible to said second arm at any selected one of said plural distances from said second pivot axis and connected to said second arm at said one of said plural distances; and 
 a third jaw connected to said support frame; 
 wherein said first and second laws are connected to said first and second arms at equal distances from the pivot axes of the respective arms, and the first, second and third jaws are positioned in relation to one another so that a cylindrical pipe within a range of pipe diameters can be gripped by contact, by said first, second and third jaws, with the exterior surface of said cylindrical pipe respectively at locations adjacent the three apices of a triangle containing the pipe axis, said ranges of pipe diameters being different for each of said plural distance; and 
 wherein said third jaw is movable along a line extending between said first and second jaws. 
 
     
     
       2. A drill pipe handling apparatus according to  claim 1 , including an actuator for moving said third jaw along said line extending between said first and second jaws. 
     
     
       3. A drill pipe handling apparatus according to  claim 1 , in which said first and second pivot axes lie parallel to each other in a common imaginary plane, and in which said third jaw is movable relative to said support frame, along said line extending between said first and second jaws, in a direction perpendicular to said imaginary plane. 
     
     
       4. A drill pipe handling apparatus according to  claim 1 , in which said first and second pivot axes lie parallel to each other in a common imaginary plane, relative to said support frame, and including an actuator for moving said third jaw, along said line extending between said first and second jaws, in a direction perpendicular to said imaginary plane. 
     
     
       5. A drill pipe handling apparatus comprising:
 a pipe gripping mechanism, said pipe gripping mechanism comprising: 
 a support frame; 
 first and second arms connected to said support frame and movable relative to said support frame respectively about first and second pivot axes; 
 a first actuator connected to said first arm and said support frame for moving said first arm about said first pivot axis; 
 a second actuator connected to said second arm and said support frame for moving said second arm about said second pivot axis; 
 a first jaw connectible to said first arm at any selected one of plural distances from said first pivot axis and connected to said first arm at one of said plural distances; 
 a second jaw connectible to said second arm at any selected one of said plural distances from said second pivot axis and connected to said second arm at said one of said plural distances; and 
 a third jaw connected to said support frame; 
 wherein said first and second jaws are connected to said first and second arms at equal distances from the pivot axes of the respective arms, and the first, second and third jaws are positioned in relation to one another so that a cylindrical pipe within a range of pipe diameters can be gripped by contact, by said first, second and third jaws, with the exterior surface of said cylindrical pipe respectively at locations adjacent the three apices of a triangle containing the pipe axis, said ranges of pipe diameters being different for each of said plural distances; and 
 wherein each of said arms is formed with plural sets of pin-receiving mounting holes, said sets of mounting holes being at different distances from the pivot axis of the arm in which they are formed, in which the first jaw includes a jaw holder having a first set of mounting holes formed therein and is mounted on the first arm by pins extending through said first set of mounting holes and through one of said sets of pin-receiving mounting holes formed in the first arm, and in which the second jaw includes a jaw holder having a second set of mounting holes formed therein and is mounted on the second arm by pins extending through said second set of mounting holes and through one of said sets of pin-receiving mounting holes formed in the second arm. 
 
     
     
       6. A drill pipe handling apparatus according to  claim 5 , in which the number of said sets of mounting holes is at least four. 
     
     
       7. A drill pipe handling apparatus comprising:
 a pipe gripping mechanism, said pipe gripping mechanism comprising: 
 a support frame; 
 first and second arms connected to said support frame and movable relative to said support frame respectively about first and second pivot axes; 
 a first actuator connected to said first arm and said support frame for moving said first arm about said first pivot axis; 
 a second actuator connected to said second arm and said support frame for moving said second arm about said second pivot axis; 
 a first jaw connectible to said first arm at any selected one of plural distances from said first pivot axis and connected to said first arm at one of said plural distances; 
 a second jaw connectible to said second arm at any selected one of said plural distances from said second pivot axis and connected to said second arm at said one of said plural distances; and 
 a third jaw connected to said support frame; 
 wherein said first and second laws are connected to said first and second arms at equal distances from the pivot axes of the respective arms, and the first, second and third jaws are positioned in relation to one another so that a cylindrical pipe within a range of pipe diameters can be gripped by contact, by said first, second and third jaws, with the exterior surface of said cylindrical pipe respectively at locations adjacent the three apices of a triangle containing the pipe axis, said ranges of pipe diameters being different for each of said plural distances; 
 wherein said drill pipe handling apparatus includes an elongated support having first and second opposite ends, said support being pivoted adjacent said first end about a horizontal pivot axis for movement of the elongated support in a vertical plane whereby the second end of the support can be raised and lowered, a pipe-supporting tray mounted on said support and slidable along said support in the direction of elongation of the support; and 
 wherein said support frame of the pipe gripping mechanism is mounted adjacent said second end of the support, and 
 said jaws are positioned to receive a length of drill pipe resting on said pipe-supporting tray. 
 
     
     
       8. A drill pipe handling apparatus according to  claim 7 , wherein said second end of the support is located between said first end of the support and said pipe gripping mechanism, and said pipe gripping mechanism is mounted for movement along said direction of elongation of the support.